Improved hinge means for a rotary solenoid armature

ABSTRACT

In a rotary solenoid having a hinged armature and converter means between the armature and a rotary shaft for transmitting arcuate pivotal movement of the armature into rotary movement of the shaft, the improvement wherein the hinge is a flexible hinge, preferably a one-piece thin metal strip, connected at one side thereof to the armature and at the other side thereof to a solenoid casing.

United States Patent Ganowsk Jul 25 1972 s41 IMPROVED HINGE MEANS FOR A3,048,749 8/1962 Koehler ..33s/274 ROTARY E ID A M TUR 3,505,629 4/1970Krautwald et a1 ..335/276 X [72] Inventor: Raymond J. Ganowsky, CliftonSprings, Primary Examiner George Harris Attorney-Schovee & Boston [73]Assignee: Cliitronics, Inc., Clifton Springs, NY. 22 Filed: Nov. 27,1970 [57] ABSTRACT {21] AppL No; 93 157 In a rotary solenoid having ahinged armature and converter means between the armature and a rotaryshaft for transmitting arcuate pivotal movement of the armature intorotary [52] :LS. CII ..335/228, movement of the shaft the improvementwherein the hinge is {g 274 276 a flexible hinge, preferably a one-piecethin metal strip, con. 21 5 nected at one side thereof to the armatureand at the other side thereof to a solenoid casing. [56] ReferencesCited UNITED STATES PATENTS 12 Claims, 3 Drawing figures 3,419,83112/1968 Ganowsky ..335/272 X IO 78 7 0 4 4e 4 40 68 6O 52 50 "II 42 N Il6 I 36 I4 HINGE MEANS FOR A ROTARY SOLENOID ARMATURE BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to rotarysolenoids of the hinged armature type and more particularly to animproved hinge for use therein.

2. Description of the Prior Art In the rotary solenoid described in U.S.Pat. No. 3,419,831, the armature is connected to the solenoid housing bya pin hinge. This construction is expensive in that the solenoid housinghas to have two broach or mill cuts on the open end, so that two earsare left, and then the ears have to be drilled and then de-burred. Thedimension separating the ears is critical due to the fact that saiddimension locates the armature in the lateral direction, which in turnlocates the armature cam race in relationship to the output shaft. lfthearmature cam race is not located in the proper position in relationshipto the cam race in the output shaft, the ball will not track properly,thereby reducing life and torque of the solenoid. The dimension betweenthe center line of the drilled holes in the ears to the axis of theshaft is also critical. This dimension also locates the armature withrespect to the shaft and has a similar effect on solenoid performanceand operation as does the abovementioned dimension between the ears. Thearmature itself also has a critical dimension in the dimension betweenthe outer surfaces of the two extensions, because this also affects thecam location. If the armature extensions fit too loosely within thehousing ears, the armature can shift from side to side causing cammismatch and stroke position change. If the armature extensions fit tootightly in the housing ears, large amounts of solenoid force are used inovercoming the friction, and the solenoid return spring has to be set attoo high a torque value for returning the armature. In summation, it canbe stated that the various inter-relationships of the various criticaldimensions is complex and results in a solenoid difficult and expensiveto control in production. Even if all parts initially fit properly, wearwould cause the solenoid to loosen up and the various dimensions tochange.

It is therefore an object of the present invention to provide anarmature hinge which is easy to locate on the housing so that the camwill be located correctly.

It is another object of the present invention to provide an armaturehinge that cannot shift from side to side and is not affected by longlife wear.

It is a further object of the present invention to provide a hinge thatis stable, has long life characteristics, has no dimensionalinter-relationships which prevent the cam from being located perfectlyevery time, and which will not wear dimensionally, so that the strokeposition will not change during the life of the solenoid.

SUMMARY OF THE PRESENT INVENTION A solenoid housing or casing ismachined with a flat top surface to receive the armature and theflexible hinge assembly of the present invention; thus all drilling,breaching, and hand de-burring of the housing is eliminated. Thearmature is a simple stamping with a'broach or mill cut on the top rearsection to form an angle nest, to which the armature side of theflexible hinge assembly of the present invention will be projectionwelded. The hinge assembly of the present invention includes a flexiblemetal strip and retainer blocks. In the housing side of the hingeassembly, the metal strip is held between a pair of retainer blockscomprising a lower housing block (to be welded to the solenoid housing)and an upper hinge block. The hinge block overlies a rear edge of thearmature, and the housing block abuts the armature, whereby the hingeblock keeps the rear edge of the armature from lifting up when thesolenoid is energized. After the housing and hinge blocks are connectedto the housing side of the metal strip, the armature side of the hingeassembly is connected to the armature. This is done in a fixture whichbutts the armature up tight against the housing block, and then anarmature block is positioned over the metal strip and is welded to theflexible hinge and to the armature, holding the hinge assembly tightlyto the armature. The flexible hinge has holes through which projectionson the retainer blocks protrude, so that when the welds are made, excessmaterial fills the holes locking the hinge in place. This insures thatthere will be a minimum of heat applied to the metal strip which couldcause warping. The armature is then precisely located, prior to weldingto the solenoid housing, by inserting a close fitting plug into the boreof the solenoid coil having a matching male ball or cam race to matchthe cam race in the armature. The armature is then clamped in the welderand welded, holding the correct position. In this manner, all productiontolerances are eliminated.

BRIEF DESCRIPTION OF THE DRAWING hinge assembly of DETAILED DESCRIPTIONOF THE PREFERRED EMBODIMENT With reference now in detail to the drawing,FIG. 1 shows a rotary solenoid 10 using a flexible hinge 12 according tothe present invention. Before describing the details of the hinge l2,brief reference will first be made, for convenience, to the constructionof the preferred rotary solenoid in which the hinge 12 of the presentinvention is used. Except for the hinge 12, the other parts of thesolenoid 10 are known, see for example, U.S. Pat. No. 3,419,831.

The solenoid 10 comprises generally a machined or formed housing 14provided with annular groove 16 in a top surface 18 thereof. A suitableannular solenoid coil winding 20, at least partly encapsulated in anepoxy resin layer 22, is positioned in the groove 16. Rigidly aflixed tothe bottom of the housing 14 are a pair of suitable mounting bolts orlugs 24. Mounted on the bottom of the housing 14 is a torsion returnspring 26 suitable for attachment to a rotary output shaft 28, forreturning the output shaft 28 to its arcuate orientation, shown in FIG.1, which it occupies when the solenoid 10 is not energized. A springretainer 30 holds the spring 26 onto a bottom surface 32 of the housing14.

The output shaft 28 is rotatably mounted, by suitable bearing means, ina suitable output shaft cylindrical bushing or bearing 34, which bearingis wedged within a central opening 36 of the housing 14.

A clapper l8 armature 40 is hingedly connected to the top surface 30 ofthe housing 14 by means of the flexible hinge 12 of the presentinvention. A dustcover 42 is connected to the housing 14 and enclosesthe armature 40. The armature 40 includes an opening 44 through which anadjustable limit screw or post 46 extends, for limiting the upwardmovement of the armature 40, and for varying the rotary stroke of theoutput shaft 28. Converter means 48 are provided between the armature 40and the output shaft 28 for imparting rotary movement to the shaft 28 inresponse to arcuate movement of the armature 40 when the solenoid 10 isenergized. The converter means 48 are preferably of the same typedescribed in detail in U.S. Pat. No. 3,419,831. The converter means 48comprises a single ball 49 that coacts with a pair of oppositelyinclining converter ball race cams 50 and 52 in the lower surface of thearmature 40 and in the upper surface of the output shaft 28,respectively.

Referring now in detail to the hinge 12 of the present invention, thehinge 12 comprises a thin, flexible metal strip 60 of generallyrectangular shape connected adjacent one side 62 thereof to the armature40 and adjacent another side 64 thereof to the top surface 18 of thehousing 14. The flexible hinge 12 comprises the thin metal strip 60 anda plurality of retainer blocks, including a housing block 66, a hingeblock 68 and an armature block 70. As is shown in FIG. 1, the hingeblock 68 is mounted with a slight overlap over the armature 40 torestrain a rear edge 72 of the armature 40 to keep it from lifting upwhen the solenoid is energized. ln assembling the hinge 12, the housingblock 66 is positioned in a fixture, the thin metal strip 60 is thenpositioned over the housing block 66, with two openings in the strip 60in register with two small projections on the housing block 66. Thehinge block 68 is then positioned in overlying relationship to the thinmetal strip 60 and the assembly is projection or spotwelded together.This assembly is then welded to the armature 40 by positioning the thinmetal strip 60 in a fixture and positioning the armature upside down andagainst the strip 60 and with the rear edge 72 of the armature 40abutting the housing block 66. Then the armature block 70 is placed overthe strip 60 adjacent the side 62 thereof and the block 70 and strip 60are welded to the armature 40. The block 70 is placed in register withthe strip 60 such that three projections in the armature block 70 (seeprojection 74 in FIG. 3) extend into three holes in the metal strip 60(see hole 76 in FIG. 3). The projection 74 in FIG. 3 is shown fordisclosure purposes as it appears prior to the projection welding step,after projection welding, the material of the projection 74 fills thehole 76. The hinge 12 must be welded tightly to the armature 40 toprevent any movement of the armature under load which would causebuckling of the thin metal strip 60 and sideways movement of thearmature 40. The buckling of the strip 60 causes fatigue in the metaleventually cracking it and once cracking occurs the crack will probablypropagate causing hinge failure. As already mentioned above, the strip60 has holes therethrough through which projections on the retainerblocks protrude so that when the weld is made, the excess material fillsthe hole locking the strip 60 in place. Also the pressure exerted by thewelder causes a clamping action between the parts so that when the weldcools, the spring is. clamped, for example, between the housing block 66and the hinge block 68. This design provides for a minimum of heat beingapplied to the strip 60 which could cause warping. If the welding wereattempted without these holes in the strip 60, or if the holes were toosmall, an excess amount of heat could be generated burning the strip 60and/or annealing and warping could ensue causing eventual failure. Onthe other hand, if the holes are too large, reliance could only beplaced on the clamping which could cause the strip 60 to work looseallowing the armature 40 to shift and resulting in degradation ofsolenoid performance. In the final assembly of the armature 40 to thecasing 14, it must be stated that for the best performance, the cam 50in the armature 40 must line up with the cam 52 in the output shaft 28,i.e., the ball 49 must track on the designed cam radius; if the radiiare different, the forces cannot be transmitted through the center lineof the ball due to cam angle mismatch, therefore, the ball would have toskid to make up for the distance it has to travel, and the skidding cancause extreme temperature increase on the surface of the ball causingpitting and eventual ball and cam failure. It is therefore imperativethat the cams match as close as possible. By having a floating armature,and a flat surface to weld upon at final assembly, the armature 40 canbe located by a close fitting plug which is inserted into the shaft boreof the bushing 34. This plug has a matching male ball or cam race tomatch the cam race in the armature-40. This locates the armature 40 sothat the cam races match perfectly. The armature is then clamped in thewelder and welded holding the correct position. In this manner allproduction tolerances are eliminated.

The plane normal to the axis of the shaft 28 and extending through thepivot line of the hinge 12 and the plane normal to the centerline of theshaft 28 and extending through the center of the converter ball 49,should come as close as possible to being the same plane. This is why ataper 78 exists on the rear top surface of the armature 40, i.e., todrop the pivot line down as close as possible to the plane through thecenter of the ball 49 and normal to the output shaft 28 axis. Anothersolution is to insert the cam 50 further into the armature 40. The lowerthe pivot line, the less friction caused at the rear of the armature 40.The preferred material for the strip 60 is 300 series stainless steelspring stock. Other materials can be used.

The invention has been described in detail with particular reference tothe preferred embodiment thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention as described hereinabove and as defined in the appendedclaims.

I claim:

1. In a rotary solenoid having a housing, an annular solenoid coilwinding within said housing, an output shaft mounted for rotary movementwithin said winding, an armature movably mounted relative to said shaftresponsive to the magnetic field of said coil winding and being hingedlyconnected to said housing for arcuate movement relative to said shaft,and converter means between said armature and said shaft for convertingarcuate movement of said armature to rotary movement of said shaft, theimprovement comprising a flexible hinge connecting said armature to saidhousing, and a plurality of retainer blocks connecting said hinge tosaid armature and said housing for preventing said armature from rockingfrom side to side and for preventing the hinged end of said armaturefrom lifiing up when said solenoid is energized.

2. The apparatus according to claim 1 wherein said flexible hinge is asingle thin metal strip welded at one side to said armature and weldedat the opposite side thereof to said housing.

3. The apparatus according to claim 1 wherein said converter meansincludes ball means and wherein the hinge line of said hinge isapproximately in the plane passing through said ball means and normal tosaid shaft.

4. In a rotary solenoid having a housing, an annular solenoid coilwinding within said housing, an output shaft mounted for rotary movementwithin said winding, an armature movably mounted relative to said shaftresponsive to the magnetic field of said coil winding and being hingedlyconnected to said housing for arcuate movement relative to said shaft,and converter means between said armature and said shaft for convertingarcuate movement of said armature to rotary movement of said shaft, theimprovement comprising a flexible hinge connecting said armature to saidhousing, said converter means including ball means, the hinge line ofsaid hinge being approximately in the plane passing through said ballmeans and normal to said shaft, and wherein said armature includes a topsurface having an angle nest, and said angle nest tapers from a topsurface of said armature down toward a bottom surface of said armature,whereby said hinge line of said flexible hinge can be positioned in theplane passing through said ball means and normal to said shaft.

5. In a rotary solenoid having a housing, an annular solenoid coilwinding within said housing, an output shaft mounted for rotary movementwithin said winding, an armature movably mounted relative to said shaftresponsive to the magnetic field of said coil winding and being hingedlyconnected to said housing for arcuate movement relative to said shaft,and converter means between said armature and said shaft for convertingarcuate movement of said armature to rotary movement of said shaft, theimprovement comprising a flexible hinge connecting said armature to saidhousing, said flexible hinge being a single thin metal strip ofgenerally rectangular shape welded at one long side thereof to saidarmature and at the other long side thereof to said housing, andincluding retainer blocks welded to said strip adjacent both of saidlong sides of said strip for keeping the strain of flexure off of theweld points of said strip.

6. The apparatus according to claim 5 wherein said retainer blocksinclude an armature block overlying said one side of said strip, and ahousing block underlying said other side of said strip and abutting saidarmature and a hinge block overlying said other side of said strip.

7. The apparatus according to claim 6 wherein said hinge block overlapssaid housing block to overlie the adjacent end of said armature toprevent said adjacent end of said armature from rising up when saidsolenoid is energized.

8. The apparatus according to claim 7 wherein said metal strip includesholes therethrough in register with projections on said blocks, andwherein the relative size of said holes and projections is such thatexcess weld material from said projections just fills said holes.

9. The apparatus according to claim 1 wherein said flexible hinge is aone-piece thin metal spring hinge.

10. The apparatus according to claim 1 wherein said housing iscylindrical and wherein said armature is substantially disc-shaped,having substantially the same circumference as that of said housing,wherein said housing includes a flat top surface and said armatureincludes a flat bottom surface overlying said flat top surface of saidhousing, said armature having a circular periphery except for a straightsection, said hinge being connected to said armature adjacent saidstraight section, and said hinge being connected to said top surface ofsaid housing at a portion thereof not overlain by said armature.

11. In a rotary solenoid having a housing, an annular solenoid coilwinding within said housing, an output shaft mounted for rotary movementwithin said winding, an annature movably mounted relative to said shaftresponsive to the magnetic field of said coil winding and being hingedlyconnected to said housing for arcuate movement relative to said shaft,and converter means between said armature and said shaft for convertingarcuate movement of said armature to rotary movement of said shaft, theimprovement comprising a flexible hinge connecting said armature to saidhousing, said housing being cylindrical, said armature beingsubstantially disc-shaped, having substantially the same circumferenceas that of said housing, said housing including a flat top surface andsaid armature including a flat bottom surface overlying said flat topsurface of said housing, said armature having a circular peripheryexcept for a straight section, said hinge being connected to saidarmature adjacent said straight section, and said hinge being connectedto said top surface of said housing at a portion thereof not overlain bysaid armature, said converter means including a ball, the top surface ofsaid armature tapering down towards said flat bottom surface of saidarmature adjacent said straight section, and wherein said hinge isconnected to said tapering portion of said armature for positioning thepivoting hinge line of said hinge in approximately the plane passingthrough the center of said ball and normal to the axis of said shaft.

12. An armature and hinge assembly for use in a rotary solenoidcomprising a flat, disc-shaped armature having a top surface and abottom surface, and having a straight edge peripheral section, a ballcam race recess in said bottom surface, an angle nest in said topsurface comprising a surface section tapering downwardly from said topsurface toward said bottom surface adjacent said straight edge section,and a flexible hinge welded to said armature at said tapering surfacesection and including a generally rectangular, flexible metal stripwelded at one long side thereof to said armature and having another longside thereof projecting beyond said straight section, and an armatureretainer block overlying said strip and welded to said armature andstrip at said one side of said strip, and a housing retainer blockunderlying said another side of said strip and a hinge block overlyingsaid another side of said strip, said housing and hinge blocks beingwelded together and to said strip with said housing block abutting saidstraight section of said armature and said hinge block slightlyoverlapping said straight section of said armature.

1. In a rotary solenoid having a housing, an annular solenoid coilwinding within said housing, an output shaft mounted for rotary movementwithin said winding, an armature movably mounted relative to said shaftresponsive to the magnetic field of said coil winding and being hingedlyconnected to said housing for arcuate movement relative to said shaft,and converter means between said armature and said shaft for convertingarcuate movement of said armature to rotary movement of said shaft, theimprovement comprising a flexible hinge connecting said armature to saidhousing, and a plurality of retainer blocks connecting said hinge tosaid armature and said housing for preventing said armature from rockingfrom side to side and for preventing the hinged end of said armaturefrom lifting up when said solenoid is energized.
 2. The apparatusaccording to claim 1 wherein said flexible hinge is a single thin metalstrip welded at one side to said armature and welded at the oppositeside thereof to said housing.
 3. The apparatus according to claim 1wherein said converter means includes ball means and wherein the hingeline of said hinge is approximately in the plane passing through saidball means and normal to said shaft.
 4. In a rotary solenoid having ahousing, an annular solenoid coil winding within said housing, an outputshaft mounted for rotary movement within said winding, an armaturemovably mounted relative to said shaft responsive to the magnetic fieldof said coil winding and being hingedly connected to said housing forarcuate movement relative to said shaft, and converter means betweensaid armature and said shaft for converting arcuate movement of saidarmature to rotary movement of said shaft, the improvement comprising aflexible hinge connecting said armature to said housing, said convertermeans including ball means, thE hinge line of said hinge beingapproximately in the plane passing through said ball means and normal tosaid shaft, and wherein said armature includes a top surface having anangle nest, and said angle nest tapers from a top surface of saidarmature down toward a bottom surface of said armature, whereby saidhinge line of said flexible hinge can be positioned in the plane passingthrough said ball means and normal to said shaft.
 5. In a rotarysolenoid having a housing, an annular solenoid coil winding within saidhousing, an output shaft mounted for rotary movement within saidwinding, an armature movably mounted relative to said shaft responsiveto the magnetic field of said coil winding and being hingedly connectedto said housing for arcuate movement relative to said shaft, andconverter means between said armature and said shaft for convertingarcuate movement of said armature to rotary movement of said shaft, theimprovement comprising a flexible hinge connecting said armature to saidhousing, said flexible hinge being a single thin metal strip ofgenerally rectangular shape welded at one long side thereof to saidarmature and at the other long side thereof to said housing, andincluding retainer blocks welded to said strip adjacent both of saidlong sides of said strip for keeping the strain of flexure off of theweld points of said strip.
 6. The apparatus according to claim 5 whereinsaid retainer blocks include an armature block overlying said one sideof said strip, and a housing block underlying said other side of saidstrip and abutting said armature and a hinge block overlying said otherside of said strip.
 7. The apparatus according to claim 6 wherein saidhinge block overlaps said housing block to overlie the adjacent end ofsaid armature to prevent said adjacent end of said armature from risingup when said solenoid is energized.
 8. The apparatus according to claim7 wherein said metal strip includes holes therethrough in register withprojections on said blocks, and wherein the relative size of said holesand projections is such that excess weld material from said projectionsjust fills said holes.
 9. The apparatus according to claim 1 whereinsaid flexible hinge is a one-piece thin metal spring hinge.
 10. Theapparatus according to claim 1 wherein said housing is cylindrical andwherein said armature is substantially disc-shaped, having substantiallythe same circumference as that of said housing, wherein said housingincludes a flat top surface and said armature includes a flat bottomsurface overlying said flat top surface of said housing, said armaturehaving a circular periphery except for a straight section, said hingebeing connected to said armature adjacent said straight section, andsaid hinge being connected to said top surface of said housing at aportion thereof not overlain by said armature.
 11. In a rotary solenoidhaving a housing, an annular solenoid coil winding within said housing,an output shaft mounted for rotary movement within said winding, anarmature movably mounted relative to said shaft responsive to themagnetic field of said coil winding and being hingedly connected to saidhousing for arcuate movement relative to said shaft, and converter meansbetween said armature and said shaft for converting arcuate movement ofsaid armature to rotary movement of said shaft, the improvementcomprising a flexible hinge connecting said armature to said housing,said housing being cylindrical, said armature being substantiallydisc-shaped, having substantially the same circumference as that of saidhousing, said housing including a flat top surface and said armatureincluding a flat bottom surface overlying said flat top surface of saidhousing, said armature having a circular periphery except for a straightsection, said hinge being connected to said armature adjacent saidstraight section, and said hinge being connected to said top surface ofsaid housing at a portion thereof not overlain by said armature, saidconverter means incluDing a ball, the top surface of said armaturetapering down towards said flat bottom surface of said armature adjacentsaid straight section, and wherein said hinge is connected to saidtapering portion of said armature for positioning the pivoting hingeline of said hinge in approximately the plane passing through the centerof said ball and normal to the axis of said shaft.
 12. An armature andhinge assembly for use in a rotary solenoid comprising a flat,disc-shaped armature having a top surface and a bottom surface, andhaving a straight edge peripheral section, a ball cam race recess insaid bottom surface, an angle nest in said top surface comprising asurface section tapering downwardly from said top surface toward saidbottom surface adjacent said straight edge section, and a flexible hingewelded to said armature at said tapering surface section and including agenerally rectangular, flexible metal strip welded at one long sidethereof to said armature and having another long side thereof projectingbeyond said straight section, and an armature retainer block overlyingsaid strip and welded to said armature and strip at said one side ofsaid strip, and a housing retainer block underlying said another side ofsaid strip and a hinge block overlying said another side of said strip,said housing and hinge blocks being welded together and to said stripwith said housing block abutting said straight section of said armatureand said hinge block slightly overlapping said straight section of saidarmature.